Add support of driving MPU9250 magnetometer connected on i2c
auxiliary bus using the MPU i2c master.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@xxxxxxxxxxxxxx>
---
drivers/iio/imu/inv_mpu6050/Makefile | 2 +-
drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 144 ++++++++-
drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h | 4 +
drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c | 355 +++++++++++++++++++++
drivers/iio/imu/inv_mpu6050/inv_mpu_magn.h | 36 +++
5 files changed, 537 insertions(+), 4 deletions(-)
create mode 100644 drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c
create mode 100644 drivers/iio/imu/inv_mpu6050/inv_mpu_magn.h
diff --git a/drivers/iio/imu/inv_mpu6050/Makefile b/drivers/iio/imu/inv_mpu6050/Makefile
index 2cfbd926522f..c103441a906b 100644
--- a/drivers/iio/imu/inv_mpu6050/Makefile
+++ b/drivers/iio/imu/inv_mpu6050/Makefile
@@ -5,7 +5,7 @@
obj-$(CONFIG_INV_MPU6050_IIO) += inv-mpu6050.o
inv-mpu6050-y := inv_mpu_core.o inv_mpu_ring.o inv_mpu_trigger.o \
- inv_mpu_aux.o
+ inv_mpu_aux.o inv_mpu_magn.o
obj-$(CONFIG_INV_MPU6050_I2C) += inv-mpu6050-i2c.o
inv-mpu6050-i2c-y := inv_mpu_i2c.o inv_mpu_acpi.o
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
index 7b2e4d81bbba..f1c65e0dd1a5 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -17,6 +17,7 @@
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include "inv_mpu_iio.h"
+#include "inv_mpu_magn.h"
/*
* this is the gyro scale translated from dynamic range plus/minus
@@ -332,6 +333,11 @@ static int inv_mpu6050_init_config(struct iio_dev *indio_dev)
*/
st->chip_period = NSEC_PER_MSEC;
+ /* magn chip init, noop if not present in the chip */
+ result = inv_mpu_magn_probe(st);
+ if (result)
+ goto error_power_off;
+
return inv_mpu6050_set_power_itg(st, false);
error_power_off:
@@ -411,6 +417,9 @@ static int inv_mpu6050_read_channel_data(struct iio_dev *indio_dev,
ret = inv_mpu6050_sensor_show(st, st->reg->temperature,
IIO_MOD_X, val);
break;
+ case IIO_MAGN:
+ ret = inv_mpu_magn_read(st, chan->channel2, val);
+ break;
default:
ret = -EINVAL;
break;
@@ -469,6 +478,8 @@ inv_mpu6050_read_raw(struct iio_dev *indio_dev,
*val2 = INV_MPU6050_TEMP_SCALE;
return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_MAGN:
+ return inv_mpu_magn_get_scale(st, chan, val, val2);
default:
return -EINVAL;
}
@@ -710,6 +721,11 @@ inv_mpu6050_fifo_rate_store(struct device *dev, struct device_attribute *attr,
if (result)
goto fifo_rate_fail_power_off;
+ /* update rate for magn, noop if not present in chip */
+ result = inv_mpu_magn_set_rate(st, fifo_rate);
+ if (result)
+ goto fifo_rate_fail_power_off;
+
fifo_rate_fail_power_off:
result |= inv_mpu6050_set_power_itg(st, false);
fifo_rate_fail_unlock:
@@ -795,8 +811,14 @@ inv_get_mount_matrix(const struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct inv_mpu6050_state *data = iio_priv(indio_dev);
+ const struct iio_mount_matrix *matrix;
+
+ if (chan->type == IIO_MAGN)
+ matrix = &data->magn_orient;
+ else
+ matrix = &data->orientation;
- return &data->orientation;
+ return matrix;
}
static const struct iio_chan_spec_ext_info inv_ext_info[] = {
@@ -864,6 +886,98 @@ static const unsigned long inv_mpu_scan_masks[] = {
0,
};
+#define INV_MPU9X50_MAGN_CHAN(_chan2, _bits, _index) \
+ { \
+ .type = IIO_MAGN, \
+ .modified = 1, \
+ .channel2 = _chan2, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_RAW), \
+ .scan_index = _index, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = _bits, \
+ .storagebits = 16, \
+ .shift = 0, \
+ .endianness = IIO_BE, \
+ }, \
+ .ext_info = inv_ext_info, \
+ }
+
+static const struct iio_chan_spec inv_mpu9250_channels[] = {
+ IIO_CHAN_SOFT_TIMESTAMP(INV_MPU9X50_SCAN_TIMESTAMP),
+ /*
+ * Note that temperature should only be via polled reading only,
+ * not the final scan elements output.
+ */
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW)
+ | BIT(IIO_CHAN_INFO_OFFSET)
+ | BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = -1,
+ },
+ INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_X, INV_MPU6050_SCAN_GYRO_X),
+ INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_Y, INV_MPU6050_SCAN_GYRO_Y),
+ INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_Z, INV_MPU6050_SCAN_GYRO_Z),
+
+ INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_X, INV_MPU6050_SCAN_ACCL_X),
+ INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_Y, INV_MPU6050_SCAN_ACCL_Y),
+ INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_Z, INV_MPU6050_SCAN_ACCL_Z),
+
+ /* Magnetometer resolution is 16 bits */
+ INV_MPU9X50_MAGN_CHAN(IIO_MOD_X, 16, INV_MPU9X50_SCAN_MAGN_X),
+ INV_MPU9X50_MAGN_CHAN(IIO_MOD_Y, 16, INV_MPU9X50_SCAN_MAGN_Y),
+ INV_MPU9X50_MAGN_CHAN(IIO_MOD_Z, 16, INV_MPU9X50_SCAN_MAGN_Z),
+};
+
+static const unsigned long inv_mpu9x50_scan_masks[] = {
+ /* 3-axis accel */
+ BIT(INV_MPU6050_SCAN_ACCL_X)
+ | BIT(INV_MPU6050_SCAN_ACCL_Y)
+ | BIT(INV_MPU6050_SCAN_ACCL_Z),
+ /* 3-axis gyro */
+ BIT(INV_MPU6050_SCAN_GYRO_X)
+ | BIT(INV_MPU6050_SCAN_GYRO_Y)
+ | BIT(INV_MPU6050_SCAN_GYRO_Z),
+ /* 3-axis magn */
+ BIT(INV_MPU9X50_SCAN_MAGN_X)
+ | BIT(INV_MPU9X50_SCAN_MAGN_Y)
+ | BIT(INV_MPU9X50_SCAN_MAGN_Z),
+ /* 6-axis accel + gyro */
+ BIT(INV_MPU6050_SCAN_ACCL_X)
+ | BIT(INV_MPU6050_SCAN_ACCL_Y)
+ | BIT(INV_MPU6050_SCAN_ACCL_Z)
+ | BIT(INV_MPU6050_SCAN_GYRO_X)
+ | BIT(INV_MPU6050_SCAN_GYRO_Y)
+ | BIT(INV_MPU6050_SCAN_GYRO_Z),
+ /* 6-axis accel + magn */
+ BIT(INV_MPU6050_SCAN_ACCL_X)
+ | BIT(INV_MPU6050_SCAN_ACCL_Y)
+ | BIT(INV_MPU6050_SCAN_ACCL_Z)
+ | BIT(INV_MPU9X50_SCAN_MAGN_X)
+ | BIT(INV_MPU9X50_SCAN_MAGN_Y)
+ | BIT(INV_MPU9X50_SCAN_MAGN_Z),
+ /* 6-axis gyro + magn */
+ BIT(INV_MPU6050_SCAN_GYRO_X)
+ | BIT(INV_MPU6050_SCAN_GYRO_Y)
+ | BIT(INV_MPU6050_SCAN_GYRO_Z)
+ | BIT(INV_MPU9X50_SCAN_MAGN_X)
+ | BIT(INV_MPU9X50_SCAN_MAGN_Y)
+ | BIT(INV_MPU9X50_SCAN_MAGN_Z),
+ /* 9-axis accel + gyro + magn */
+ BIT(INV_MPU6050_SCAN_ACCL_X)
+ | BIT(INV_MPU6050_SCAN_ACCL_Y)
+ | BIT(INV_MPU6050_SCAN_ACCL_Z)
+ | BIT(INV_MPU6050_SCAN_GYRO_X)
+ | BIT(INV_MPU6050_SCAN_GYRO_Y)
+ | BIT(INV_MPU6050_SCAN_GYRO_Z)
+ | BIT(INV_MPU9X50_SCAN_MAGN_X)
+ | BIT(INV_MPU9X50_SCAN_MAGN_Y)
+ | BIT(INV_MPU9X50_SCAN_MAGN_Z),
+ 0,
+};
+
static const struct iio_chan_spec inv_icm20602_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(INV_ICM20602_SCAN_TIMESTAMP),
{
@@ -1145,6 +1259,11 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
return result;
}
+ /* fill magnetometer orientation */
+ result = inv_mpu_magn_set_orient(st);
+ if (result)
+ return result;
+
/* power is turned on inside check chip type*/
result = inv_check_and_setup_chip(st);
if (result)
@@ -1168,14 +1287,33 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
if (inv_mpu_bus_setup)
inv_mpu_bus_setup(indio_dev);
- if (chip_type == INV_ICM20602) {
+ switch (chip_type) {
+ case INV_MPU9250:
+ case INV_MPU9255:
+ /*
+ * Use magnetometer inside the chip only if there is no i2c
+ * auxiliary device in use.
+ */
+ if (!st->magn_disabled) {
+ indio_dev->channels = inv_mpu9250_channels;
+ indio_dev->num_channels = ARRAY_SIZE(inv_mpu9250_channels);
+ indio_dev->available_scan_masks = inv_mpu9x50_scan_masks;
+ } else {
+ indio_dev->channels = inv_mpu_channels;
+ indio_dev->num_channels = ARRAY_SIZE(inv_mpu_channels);
+ indio_dev->available_scan_masks = inv_mpu_scan_masks;
+ }
+ break;
+ case INV_ICM20602:
indio_dev->channels = inv_icm20602_channels;
indio_dev->num_channels = ARRAY_SIZE(inv_icm20602_channels);
indio_dev->available_scan_masks = inv_icm20602_scan_masks;
- } else {
+ break;
+ default:
indio_dev->channels = inv_mpu_channels;
indio_dev->num_channels = ARRAY_SIZE(inv_mpu_channels);
indio_dev->available_scan_masks = inv_mpu_scan_masks;
+ break;
}
indio_dev->info = &mpu_info;
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
index 04215bc6e8ab..953f85618199 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -130,6 +130,8 @@ struct inv_mpu6050_hw {
* @data_timestamp: timestamp for next data sample.
* @vddio_supply voltage regulator for the chip.
* @magn_disabled: magnetometer disabled for backward compatibility reason.
+ * @magn_raw_to_gauss: coefficient to convert mag raw value to Gauss.
+ * @magn_orient: magnetometer sensor chip orientation if available.
*/
struct inv_mpu6050_state {
struct mutex lock;
@@ -152,6 +154,8 @@ struct inv_mpu6050_state {
s64 data_timestamp;
struct regulator *vddio_supply;
bool magn_disabled;
+ s32 magn_raw_to_gauss[3];
+ struct iio_mount_matrix magn_orient;
};
/*register and associated bit definition*/
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c
new file mode 100644
index 000000000000..415d8acece54
--- /dev/null
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c
@@ -0,0 +1,355 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 TDK-InvenSense, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/string.h>
+
+#include "inv_mpu_iio.h"
+#include "inv_mpu_aux.h"
+
+/*
+ * MPU9250 magnetometer is an AKM AK8963 chip on I2C aux bus
+ */
+#define INV_MPU_MAGN_I2C_ADDR 0x0C
+
+#define INV_MPU_MAGN_REG_WIA 0x00
+#define INV_MPU_MAGN_BITS_WIA 0x48
+
+#define INV_MPU_MAGN_REG_ST1 0x02
+#define INV_MPU_MAGN_BIT_DRDY 0x01
+#define INV_MPU_MAGN_BIT_DOR 0x02
+
+#define INV_MPU_MAGN_REG_DATA 0x03
+
+#define INV_MPU_MAGN_REG_ST2 0x09
+#define INV_MPU_MAGN_BIT_HOFL 0x08
+#define INV_MPU_MAGN_BIT_BITM 0x10
+
+#define INV_MPU_MAGN_REG_CNTL1 0x0A
+#define INV_MPU_MAGN_BITS_MODE_PWDN 0x00
+#define INV_MPU_MAGN_BITS_MODE_SINGLE 0x01
+#define INV_MPU_MAGN_BITS_MODE_FUSE 0x0F
+#define INV_MPU_MAGN_BIT_OUTPUT_BIT 0x10
+
+#define INV_MPU_MAGN_REG_CNTL2 0x0B
+#define INV_MPU_MAGN_BIT_SRST 0x01
+
+#define INV_MPU_MAGN_REG_ASAX 0x10
+#define INV_MPU_MAGN_REG_ASAY 0x11
+#define INV_MPU_MAGN_REG_ASAZ 0x12
+
+/* Magnetometer maximum frequency */
+#define INV_MPU_MAGN_FREQ_HZ_MAX 50
+
+static bool inv_magn_supported(const struct inv_mpu6050_state *st)
+{
+ switch (st->chip_type) {
+ case INV_MPU9250:
+ case INV_MPU9255:
+ return true;
+ default:
+ return false;
+ }
+}
+
+/* init magnetometer chip */
+static int inv_magn_init(struct inv_mpu6050_state *st)
+{
+ uint8_t val;
+ uint8_t asa[3];
+ int ret;
+
+ /* check whoami */
+ ret = inv_mpu_aux_read(st, INV_MPU_MAGN_I2C_ADDR, INV_MPU_MAGN_REG_WIA,
+ &val, sizeof(val));
+ if (ret)
+ return ret;
+ if (val != INV_MPU_MAGN_BITS_WIA)
+ return -ENODEV;
+
+ /* reset chip */
+ ret = inv_mpu_aux_write(st, INV_MPU_MAGN_I2C_ADDR,
+ INV_MPU_MAGN_REG_CNTL2,
+ INV_MPU_MAGN_BIT_SRST);
+ if (ret)
+ return ret;
+
+ /* read fuse ROM data */
+ ret = inv_mpu_aux_write(st, INV_MPU_MAGN_I2C_ADDR,
+ INV_MPU_MAGN_REG_CNTL1,
+ INV_MPU_MAGN_BITS_MODE_FUSE);
+ if (ret)
+ return ret;
+
+ ret = inv_mpu_aux_read(st, INV_MPU_MAGN_I2C_ADDR, INV_MPU_MAGN_REG_ASAX,
+ asa, sizeof(asa));
+ if (ret)
+ return ret;
+
+ /* switch back to power-down */
+ ret = inv_mpu_aux_write(st, INV_MPU_MAGN_I2C_ADDR,
+ INV_MPU_MAGN_REG_CNTL1,
+ INV_MPU_MAGN_BITS_MODE_PWDN);
+ if (ret)
+ return ret;
+
+ /*
+ * Sensitivity adjustement and scale to Gauss
+ *
+ * Hadj = H * (((ASA - 128) * 0.5 / 128) + 1)
+ * Factor simplification:
+ * Hadj = H * ((ASA + 128) / 256)
+ *
+ * Sensor sentivity
+ * 0.15 uT in 16 bits mode
+ * 1 uT = 0.01 G and value is in micron (1e6)
+ * sensitvity = 0.15 uT * 0.01 * 1e6
+ *
+ * raw_to_gauss = Hadj * 1500
+ */
+ st->magn_raw_to_gauss[0] = (((int32_t)asa[0] + 128) * 1500) / 256;
+ st->magn_raw_to_gauss[1] = (((int32_t)asa[1] + 128) * 1500) / 256;
+ st->magn_raw_to_gauss[2] = (((int32_t)asa[2] + 128) * 1500) / 256;
+
+ return 0;
+}
+
+/**
+ * inv_mpu_magn_probe() - probe and setup magnetometer chip
+ * @st: driver internal state
+ *
+ * Returns 0 on success, a negative error code otherwise
+ *
+ * It is probing the chip and setting up all needed i2c transfers.
+ * Noop if there is no magnetometer in the chip.
+ */
+int inv_mpu_magn_probe(struct inv_mpu6050_state *st)
+{
+ int ret;
+
+ /* quit if chip is not supported */
+ if (!inv_magn_supported(st))
+ return 0;
+
+ /* configure i2c master aux port */
+ ret = inv_mpu_aux_init(st);
+ if (ret)
+ return ret;
+
+ /* check and init mag chip */
+ ret = inv_magn_init(st);
+ if (ret)
+ return ret;
+
+ /*
+ * configure mpu i2c master accesses
+ * i2c SLV0: read sensor data, 7 bytes data(6)-ST2
+ * Byte swap data to store them in big-endian in impair address groups
+ */
+ ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_ADDR(0),
+ INV_MPU6050_BIT_I2C_SLV_RNW | INV_MPU_MAGN_I2C_ADDR);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_REG(0),
+ INV_MPU_MAGN_REG_DATA);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0),
+ INV_MPU6050_BIT_SLV_EN |
+ INV_MPU6050_BIT_SLV_BYTE_SW |
+ INV_MPU6050_BIT_SLV_GRP |
+ INV_MPU9X50_BYTES_MAGN);
+ if (ret)
+ return ret;
+
+ /* i2c SLV1: launch single measurement */
+ ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_ADDR(1),
+ INV_MPU_MAGN_I2C_ADDR);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_REG(1),
+ INV_MPU_MAGN_REG_CNTL1);
+ if (ret)
+ return ret;
+
+ /* add 16 bits mode */
+ ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_DO(1),
+ INV_MPU_MAGN_BITS_MODE_SINGLE |
+ INV_MPU_MAGN_BIT_OUTPUT_BIT);
+ if (ret)
+ return ret;
+
+ return regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(1),
+ INV_MPU6050_BIT_SLV_EN | 1);
+}
+
+/**
+ * inv_mpu_magn_set_rate() - set magnetometer sampling rate
+ * @st: driver internal state
+ * @fifo_rate: mpu set fifo rate
+ *
+ * Returns 0 on success, a negative error code otherwise
+ *
+ * Limit sampling frequency to the maximum value supported by the
+ * magnetometer chip. Resulting in duplicated data for higher frequencies.
+ * Noop if there is no magnetometer in the chip.
+ */
+int inv_mpu_magn_set_rate(const struct inv_mpu6050_state *st, int fifo_rate)
+{
+ uint8_t d;
+
+ /* quit if chip is not supported */
+ if (!inv_magn_supported(st))
+ return 0;
+
+ /*
+ * update i2c master delay to limit mag sampling to max frequency
+ * compute fifo_rate divider d: rate = fifo_rate / (d + 1)
+ */
+ if (fifo_rate > INV_MPU_MAGN_FREQ_HZ_MAX)
+ d = fifo_rate / INV_MPU_MAGN_FREQ_HZ_MAX - 1;
+ else
+ d = 0;
+
+ return regmap_write(st->map, INV_MPU6050_REG_I2C_SLV4_CTRL, d);
+}
+
+/**
+ * inv_mpu_magn_set_orient() - fill magnetometer mounting matrix
+ * @st: driver internal state
+ *
+ * Returns 0 on success, a negative error code otherwise
+ *
+ * Fill magnetometer mounting matrix using the provided chip matrix.
+ */
+int inv_mpu_magn_set_orient(struct inv_mpu6050_state *st)
+{
+ const char *orient;
+ char *str;
+ int i;
+
+ /* fill magnetometer orientation */
+ switch (st->chip_type) {
+ case INV_MPU9250:
+ case INV_MPU9255:
+ /* x <- y */
+ st->magn_orient.rotation[0] = st->orientation.rotation[3];
+ st->magn_orient.rotation[1] = st->orientation.rotation[4];
+ st->magn_orient.rotation[2] = st->orientation.rotation[5];
+ /* y <- x */
+ st->magn_orient.rotation[3] = st->orientation.rotation[0];
+ st->magn_orient.rotation[4] = st->orientation.rotation[1];
+ st->magn_orient.rotation[5] = st->orientation.rotation[2];
+ /* z <- -z */
+ for (i = 0; i < 3; ++i) {
+ orient = st->orientation.rotation[6 + i];
+ /* use length + 2 for adding minus sign if needed */
+ str = devm_kzalloc(regmap_get_device(st->map),
+ strlen(orient) + 2, GFP_KERNEL);
+ if (str == NULL)
+ return -ENOMEM;
+ if (strcmp(orient, "0") == 0) {
+ strcpy(str, orient);
+ } else if (orient[0] == '-') {
+ strcpy(str, &orient[1]);
+ } else {
+ str[0] = '-';
+ strcpy(&str[1], orient);
+ }
+ st->magn_orient.rotation[6 + i] = str;
+ }
+ break;
+ default:
+ st->magn_orient = st->orientation;
+ break;
+ }
+
+ return 0;
+}
+
+/**
+ * inv_mpu_magn_read() - read magnetometer data
+ * @st: driver internal state
+ * @axis: IIO modifier axis value
+ * @val: store corresponding axis value
+ *
+ * Returns 0 on success, a negative error code otherwise
+ */
+int inv_mpu_magn_read(const struct inv_mpu6050_state *st, int axis, int *val)
+{
+ unsigned int user_ctrl, status;
+ __be16 data[3];
+ uint8_t addr;
+ uint8_t d;
+ unsigned int period_ms;
+ int ret;
+
+ /* quit if chip is not supported */
+ if (!inv_magn_supported(st))
+ return -ENODEV;
+
+ /* Mag data: X - Y - Z */
+ switch (axis) {
+ case IIO_MOD_X:
+ addr = 0;
+ break;
+ case IIO_MOD_Y:
+ addr = 1;
+ break;
+ case IIO_MOD_Z:
+ addr = 2;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* set sample rate to max mag freq */
+ d = INV_MPU6050_FIFO_RATE_TO_DIVIDER(INV_MPU_MAGN_FREQ_HZ_MAX);
+ ret = regmap_write(st->map, st->reg->sample_rate_div, d);
+ if (ret)
+ return ret;
+
+ /* start i2c master, wait for xfer, stop */
+ user_ctrl = st->chip_config.user_ctrl | INV_MPU6050_BIT_I2C_MST_EN;
+ ret = regmap_write(st->map, st->reg->user_ctrl, user_ctrl);
+ if (ret)
+ return ret;
+
+ /* need to wait 2 periods + half-period margin */
+ period_ms = 1000 / INV_MPU_MAGN_FREQ_HZ_MAX;
+ msleep(period_ms * 2 + period_ms / 2);
+ user_ctrl = st->chip_config.user_ctrl;
+ ret = regmap_write(st->map, st->reg->user_ctrl, user_ctrl);
+ if (ret)
+ return ret;
+
+ /* restore sample rate */
+ d = st->chip_config.divider;
+ ret = regmap_write(st->map, st->reg->sample_rate_div, d);
+ if (ret)
+ return ret;
+
+ /* check i2c status and read raw data */
+ ret = regmap_read(st->map, INV_MPU6050_REG_I2C_MST_STATUS, &status);
+ if (ret)
+ return ret;
+
+ if (status & INV_MPU6050_BIT_I2C_SLV0_NACK ||
+ status & INV_MPU6050_BIT_I2C_SLV1_NACK)
+ return -EIO;
+
+ ret = regmap_bulk_read(st->map, INV_MPU6050_REG_EXT_SENS_DATA,
+ data, sizeof(data));
+ if (ret)
+ return ret;
+
+ *val = (int16_t)be16_to_cpu(data[addr]);
+
+ return IIO_VAL_INT;
+}
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.h
new file mode 100644
index 000000000000..b41bd0578478
--- /dev/null
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 TDK-InvenSense, Inc.
+ */
+
+#ifndef INV_MPU_MAGN_H_
+#define INV_MPU_MAGN_H_
+
+#include <linux/kernel.h>
+
+#include "inv_mpu_iio.h"
+
+int inv_mpu_magn_probe(struct inv_mpu6050_state *st);
+
+/**
+ * inv_mpu_magn_get_scale() - get magnetometer scale value
+ * @st: driver internal state
+ *
+ * Returns IIO data format.
+ */
+static inline int inv_mpu_magn_get_scale(const struct inv_mpu6050_state *st,
+ const struct iio_chan_spec *chan,
+ int *val, int *val2)
+{
+ *val = 0;
+ *val2 = st->magn_raw_to_gauss[chan->address];
+ return IIO_VAL_INT_PLUS_MICRO;
+}
+
+int inv_mpu_magn_set_rate(const struct inv_mpu6050_state *st, int fifo_rate);
+
+int inv_mpu_magn_set_orient(struct inv_mpu6050_state *st);
+
+int inv_mpu_magn_read(const struct inv_mpu6050_state *st, int axis, int *val);
+
+#endif /* INV_MPU_MAGN_H_ */
--
2.17.1
